Space: The Moon Is Brown

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Had it been shot on earth, it would hardly have been worth a first glance. Its composition was uninspired and its subject — a rough-surfaced grey rock lying on brownish grey, clumpy soil —was singularly dull. Yet it was a histor ic picture — a color photograph taken on the surface of the moon. The dis tinguished and prolific photographer: Surveyor 1.

To achieve lunar color photography, Jet Propulsion Laboratory scientists in Pasadena first commanded the mirror mounted above Surveyor's fixed, black-and-white television camera to swivel and tilt until it reflected the proper piece of lunar terrain into the cam era lens. By radioed signal, they start ed a filter wheel turning until a red filter was in front of the lens. Then they ordered the camera to photograph the scene. The procedure was repeated twice more, once with a green and finally with a blue filter.

In Pasadena, Surveyor's TV trans missions were converted into three black-and-white transparencies that had subtle differences in shading caused by Surveyor's filters. Each was mounted in a separate projector — one equipped with a red, another with a green, and the third with a blue filter—and focused on a single screen. The result: a reconstituted color picture that is "a fair approximation of the actual scene."

Eerie Earthlight. Black-and-white photographs transmitted by Surveyor, before it went into hibernation last week for the 14-day lunar night, were even more remarkable. As the sun slowly sank toward the moon's horizon, the lengthening shadows cast by Surveyor itself appeared with startling clarity in shots of nearby terrain. In one picture, the 10-ft.-high spaceship's shadow stretched 50 ft. away. At sunset, the camera, aimed directly at the solar fireball, captured the brilliant halo of the sun's corona—usually invisible on earth because of the terrestrial atmosphere. After nightfall, Surveyor successfully took the last of the 10,338 photographs it has shot since June 2, when it settled on the moon. The four-minute time exposure showed one of its footpads illuminated only by eerie earthlight—the sunlight reflected off the earth.

With Surveyor's graphic pictures and clear telemetry before them, scientists were able to draw their firmest conclusions yet about the lunar terrain. At a Washington press conference, they announced that the moon's surface pre sented no great obstacles to a manned lunar landing; its consistency is almost earthlike, and its bearing strength —about 5 Ibs. per sq. in.—is more than enough to support the weight of Apollo's Lunar Excursion Module. "In one sentence," said JPL Project Scientist Leonard Jaffe, "the moon surface looks like a soil, not very hard, with rocks and clods on it and in it."

Scientific Rhapsody. Its work done for the lunar day, Surveyor reported that its batteries were charged nearly to capacity, giving scientists added hope that the craft could be revived after sunrise on June 29. To conserve electrical energy, Surveyor sent occasional reports on its condition for only the first few days of the lunar night, then lapsed into silence, using electricity only for small thermal-control heaters, which protect electronic equipment that could be damaged by extreme cold.